Conventionally, there is known a transmission formed of an automated manual transmission in which the clutch of a manual transmission is automated.
In this transmission, as in the case of a transmission formed of a manual transmission (M/T), a plurality of shift gears of a main shaft and a plurality of shift gears of a counter shaft all rotate while being constantly meshed. Each shift gear of the counter shaft is connected to the counter shaft at idle. A sleeve, which is associated in a one-to-one correspondence with each shift gear, is inserted to a desired shift gear to thereby couple that shift gear to the counter shaft so as to be integrally rotatable. Each sleeve is engaged with any one of a plurality of shift forks, and the shift fork is driven to change between insertion and non-insertion of a corresponding one of the sleeves. In addition, a select mechanism that selects the shift fork, which is a target to be driven, from among the plurality of shift forks is provided.
For example, as described in Patent Document 1, in a transmission of this type, shift forks are driven by the driving force of an electric actuator, typically, such as an air cylinder. Various transmitting members are interposed between the electric actuator and the shift forks so that driving force from the electric actuator is transmittable to the shift forks, and shift operation for driving the shift forks is performed by the driving force of the electric actuator.
In addition, further another electric actuator is provided for the transmission. Various transmitting members are interposed between the electric actuator and the select mechanism such that driving force from the electric actuator is transmittable to the select mechanism, and select operation for selecting the shift fork, which is a target to be driven, is performed by the driving force of the electric actuator.
In addition, Patent Document 2 describes the technique that employs electric motors instead of electric actuators as electric driving members. In this configuration, shift operation is performed by the rotational driving force of a first electric motor, and select operation is performed by the rotational driving force of a second electric motor.